Induction-motor armature.



BATENTED MAY26 E. THOMSON. INDUCTION MOTOR ARMATURE.

APPLICATION FILED JAN. 28. 1903.

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Witnesses. Irfiventor. Elihu Thomson 110.7%,449. PATENTEDMAY 26, 1903. 'E. THOMSON.

INDUCTION MOTGR ARMATURE.

APPLICATION FILED us. as. 1903. k V

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no 10mm. 7 7 Fig.5. Fig.6. Figlw Witnesses. Inventcr 7 LEM Elihu Thomson. lf 7 UNITED STATES PATENT.

Patented May 26, 1 903.

OFFICE.

ELIH-U THOMSON, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION" OF NEW YORK.

INDUCTION-MOTOR ARMATURE.

SPECIFICATION forming part of Letters Patent No. 729,449, dated May 26, 1903.

Application filed January 28, 1903. Serial No. 140,885. (No model.)

have invented certain new and useful Improvements in Induction-Motor Armatures, of which the following is a specification.

This invention relates to the armatures of dynamo-electric machines, and more particularly to induction-motor armatures of the squirrel-cage type, in which bars or conductors of copper rest in slots or are strung through holes in sheet-metal laminae. Heretofore it has been the practice in the construction of armatures of this type to make each lamina a complete ring where the diameter of the armature is small, and to cut the ring into halves, thirds, or slightly-shorter segme'nts where the diameter of the armature is greater, and to punch therein a large number of openings or slots for theconductor' bars or rods; but in cutting or punching such rings or segments for the construction of armatures of difierent diameters it is necessary to cut the rings also of different diameters. This necessitates the use of different dies and the loss of time in changing from Punchings made for an armature of one diameter cannot be used in the construction of an armature of a different diameter; but each .armature must have its specially-preparec punchings.

One of the objects of my invention is to so cut or punch these segments that the same punchings may be used in building up armatures of different diameters. By my invention standard punchings may be made, and from these a number of varying sizes of armatures may be built.

ments much shorter than has been the practice heretofore and by so shaping their ends that adjacent pieces may be assembled at different angles to each other. This construction permits the same segments to be used in armatures of varying diameters, and where my invention is applied in the manufacture of squirrel-cage armatures the conductor-bars not only will not interfere with the assembling of the segments in the manner above This object, generally stated, is accomplished by cutting the'seg-' noted, but they may be employed to bind the segments together.

Myinvention also provides for the construction of armatures in a simple Way without expensive dies and in a manner to use up almost all of the sheet-metal stock, and it permits the outer surface of the armature to be made smooth or slotted, as desired.

Other objects and advantages will appear in the more detailed description hereinafter given.

The construction illustrated in the accompanying drawings, together with the description herein set forth, discloses one embodiment of my invention.

In the drawings, Figure 1 is an end view of an armature of the type specified, with the armature-shaft and conductor-bars shown in section and without the end conductor-rings in place. Fig. 2 is a side View of the same with the end rings in place and with parts broken away and other parts in section, the

section being taken on the line 2 2 of Fig. 1. Figs. 3 and 4 are top and edge views, respecblage of segments of the form shown in Fig. 6.

Similar characters refer to similar parts throughout the several views.

.The armature consists, essentially, of the hub A, keyed at its center to the-shaft B and connected at its periphery with the laminated structure C. Thislaminated structure is held between the end conductor-rings 10, which are electrically and mechanically connected to the conductor-rods 11, upon which are assembled the segments of sheet metal constituting the laminated structure. segments may be punched in a variety of shapes, but all possess the characteristics These that when any two are assembled end to end it is always possible to move one relative to the other in their common plane. In assembling them upon the conductor-rods 11 the joints may be overlapped more or less frequently,but preferablyin every layer, as illustrated in Figs. 1 and 2. The conductor-rods 11 are arranged so that a certain definite nu mber of segmental pieces will make up a complete ring, and they may be insulated in any preferred manner, such as by enameling them orsurrounding them by thin hard paper tubes, as indicated at 18. WVhen all the segments have been assembled, the end conductorrings 10, which may be complete copper rings, as illustrated in Fig. 2, or built-up rings, as illustrated in Figs. 3 and 4, are soldered or otherwise secured to the conductor-rods 11. The hub A is next put in place. This may be done by making the hub tapering and forcing it into the circular opening made by the assembled segments or by keying the end rings to the hub A, as indicated at 14:. The key might also extend beyond the end rings into the laminated structure, in which case the segments would be properly slotted for the reception of the key.

The segmental pieces may be strung on the rods 11 not only as illustrated in Figs. 1 and 2, where they overlap by halvesthat is, where the ends of the segments in every other layer fall in straight lines-but they may be overlapped by thirds, as illustrated in Figs. 15 and 16. Where the segments are cut so as to be used in overlapping by halves, they are provided with two openings, which may be very accurately punched; but where the segments are to be overlapped by thirds three openings are necessary. In order to provide for the use of segments having three openings in armatures of difierent diameters, the three openings should not be accurately punched, since in that case they would determine adefiuite circu m ference,which could existforonlyonediameterofarmature. Byaccurately punched I mean segments punched with openings of the same size as the rods 11 and around which they will snugly fit. In segments having three openings the end openings may be accurately punched, provided the center opening is slightly elongated radially, as shown at 14 and 16 in segments 15 and 17, respectively. It is preferable to lap by thirds where the number of conductorrods 11 is large and the cross-section of the iron between the conductors small. By this lapping the completed structure is also well tied together. Where there are more than three openings, as in segment 19, two of the openings should be accurately punched and the others slightly elongated, as shown at 18.

It of course is not necessary that the holes be entirely symmetrical. In fact, it may be advisable to displace them to one side, as illustrated in segment 17, Fig. 10, in order to secure more complete and perfect linkage with ample strength around the holes upon which the strain comes.

The openings in the segments need not be circular.

In Fig. 8 the openings 20 are shown more or less rectangular. The dotted lines in this figure also show how the segments 19 are to be lapped.

In Fig. 9 the openings 21 in the segment 22 are similar to the openings 20, but open at one end in the form of slots.

In Fig. 7 is illustrated another modification, in which the segment 23 is provided with openings 24:, which are similar to the circular openings 25 of segment 26, but open at the outer side of the segment, so as to form a slotted opening.

Another modified segmentis thatillustrated in Figs. 11 and 12 and designated 27. Its form is such as to fit over a channel-shaped conductor-bar 28. This channel-shaped conductor and the segmental pieces fit closely together at all points except those designated 29 and 30. At these points the fit may be close or not, depending upon the diameter of the armature in the construction of which these segments are used. \Vhere the diameter of the armature is the largest in which a given standard segment of this pattern may be used, the fit between the segment 27 and the conductor-bar 28 at the point 30 will be close, as illustrated in Fig. 11, and where the diameter is the smallest the fit at the point 29 will be close. In this form the assembled segments 27 overlap and break joint, just as in the previous forms, and the conductor-bars 28 lock the segments together when in place.

It is not necessary that all the segmental pieces be curved upon their outer and inner edges, as are the segments 12, 15, 17, 19, 22, and 27. The inner edge may be straight and the outer edge curved, as illustrated in segments 23 and 26, or both inner and outer edges may be straight and parallel, as in the segment 31. The segment 31 is preferably used in constructing armatures of large diameter. Where this is done, it will be seen that the inner surface of the assembled segments approximates a circle with sufficient accuracy for placing them in position on the hub A. It may be pointed out that in all these forms the magnetic continuity is established by the overlapping pieces, and as the flux in the armature at high speed is of very low periodicity numerous overlappings do not lead to any considerable energy losses, such as might be the case if high-periodicity eflects were produced therein.

Instead of the continuous copper ring conductors 10 the ring conductors may be built up by connecting together electrically and mechanically copper segments 32 in any convenient manner, as by soldering. These copper segments are made heavier, but of the same general shape as the sheet-iron segments. Such a construction is illustrated in Figs. 3 and 4:, in which these copper segments are shown provided with openings for the reception of the conductor-rods 11, to which they may be connected by riveting.

It will be obvious that many other forms and modifications than those shown and described may be employed without departing from the spirit of my invention.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In the laminated structure of an armature, the combination of sheet-metal pieces constituting said structure, so shaped that they may be assembled at different angles relative to each other, and means for holding said sheet-metal pieces together.

2. In the laminated structure of an armature, the combination of sheet-metal pieces constituting said structure, so shaped that they may be assembled at diiferent angles relative to each other, and conductor-rods for holding said sheet-metal pieces together.

3. In the laminated structure of an arma ture, the sheetmetal pieces forming said structure so constructed and arranged that said pieces may be assembled at different angles relative to each other.

4. In an armature, the combination of end conductors, conductor-bars extending therebetween, and a laminated structure of sheet metal held in place thereby, the sheets of metal composing said laminae being so shaped ranged that said plates may be assembled at different angles to each other, and conductorbars mechanically and electrically connected thereto.

7. In an induction-motor armature, the combi nation of end conductors composed of a se ries of conductorplates so shaped and ar ranged that said plates may be assembled at different angles to each other, conductorbars mechanically and electrically connected thereto, and a laminated structure located between said end conductors and held in place by said end conductors and conductor-bars.

In witness whereof I have hereunto set my hand this 26th day of January, 1903.

ELIHU- THOMSON.

Witnesses:

DUGALD MoK. MOKILLOP,

JOHN J. WALKER. 

